阅读说明：本技术 Led模压封装胶片的使用方法 (Using method of LED mould pressing packaging film ) 是由 朱宥豪 蔡东庭 林佳民 于 2020-07-17 设计创作，主要内容包括：本发明公开了一种LED模压封装胶片的使用方法,其初期为由A剂、B剂、C剂和D剂组成的呈液态的混合物,使用时先将A剂和C剂常温混合静置形成初步混合物,再将初步混合物依次与B剂和D剂混合搅拌均匀并经真空脱泡得稠胶状混合物,将该稠胶状混合物涂布于离型底材上并经烘烤及常温静置后得可回熔片状或连续卷状固态胶片；使用固态胶片进行模压封装LED时,将撕除离型底材后的固态胶片覆盖在位于封装模具内的LED上方,经一定温度于短时间内使固态胶片回熔成粘稠状胶水包覆LED,并随着模压时间的增长使粘稠状胶水再固化将LED封装定型。(The invention discloses a method for using an LED mould pressing packaging film, which comprises the steps of mixing and standing an agent A and an agent C at normal temperature to form a primary mixture, mixing and stirring the primary mixture, the agent B and the agent D uniformly in sequence, defoaming in vacuum to obtain a thick gelatinous mixture, coating the thick gelatinous mixture on a release substrate, baking and standing at normal temperature to obtain a remeltable flaky or continuous coiled solid film at the initial stage, wherein the liquid mixture is composed of the agent A, the agent B, the agent C and the agent D; when the solid-state film is used for carrying out die pressing packaging on the LED, the solid-state film with the release substrate removed covers the LED positioned in the packaging die, the solid-state film is melted back into viscous glue to cover the LED in a short time at a certain temperature, and the viscous glue is cured to package and shape the LED along with the increase of the die pressing time.)

1. The use method of the LED die pressing packaging film is characterized by comprising the following steps:

(1) mixing 90-110 parts by weight of the agent A and 20-50 parts by weight of the agent C at normal temperature, stirring for 20-60min, and standing for 20min-24h to obtain a primary mixture; wherein

The agent A consists of a composition comprising the following components: 40-70 wt.% cycloaliphatic epoxy resin and 27-57 wt.% bisphenol a epoxy resin;

the agent C consists of a composition comprising the following components: 92-98 wt.% of bifunctional amine curing agent and 1-3 wt.% of phosphorus-containing catalyst;

(2) mixing the preliminary mixture obtained in the step (1) with 70-140 parts by weight of the agent B, stirring for 10-50min, then adding 5-45 parts by weight of the agent D, mixing, and continuing stirring for 10-30min to obtain a thick colloidal mixture, wherein in the mixing and stirring process, a vacuum defoaming machine is used for defoaming; wherein

The agent B consists of a composition comprising the following components: 80-95 wt.% of a phthalic anhydride mixture comprising at least hexahydrophthalic anhydride and methyl hexahydrophthalic anhydride, 1-12 wt.% of a polyester diol, 0.5-3.0 wt.% of a phosphorus-containing catalyst, and 1-3 wt.% of an aliphatic polyol;

The agent D consists of a composition comprising the following components: 90-99.9 wt.% of inorganic powder and 0.1-10 wt.% of surface tension control agent;

(3) uniformly coating the thick colloidal mixture prepared in the step (2) on a release substrate by adopting a wet coating mode, and baking at 70-130 ℃ for 1-3h to form a colloidal layer with the thickness of 10-200 mu m;

(4) standing the colloid layer obtained in the step (3) at normal temperature for 20-120min to obtain a meltable flaky solid film which is in a single sheet shape or a continuous roll shape;

(5) and (4) removing the release substrate from the sheet-shaped solid rubber sheet which can be melted back in the step (4), covering the sheet-shaped solid rubber sheet on the LED particles in the mould pressing mould, heating at the temperature of 100-.

2. The method of using the LED die attach encapsulant as claimed in claim 1, wherein: and (4) covering the solid film which is obtained in the step (4) and can be melted back with a protective layer.

3. The method of using the LED die attach encapsulant as claimed in claim 2, wherein: the protective layer is PE, PVC, EVA, PET or release paper.

4. The method of using the LED die-molding packaging film according to claim 1, 2 or 3, wherein: the release substrate is PET.

5. The method of using the LED die-pressing packaging film as claimed in claim 4, wherein: the agent a further comprises adhesion promoter 0.5-2.0 wt.%, defoamer 0.1-2.0 wt.%, first antioxidant 0.5-2.0 wt.% and first heat stabilizer 0.5-2.0 wt.%.

6. The method of using the LED die-pressing packaging film as claimed in claim 4, wherein: the mass percent content of the hexahydrophthalic anhydride in the phthalic anhydride mixture is at least 60 wt%, and the mass percent content of the methyl hexahydrophthalic anhydride in the phthalic anhydride mixture is at least 15 wt%, based on the total mass of the phthalic anhydride mixture in the agent B; the polyester diol in the agent B is aliphatic polycarbonate diol; the phosphorus-containing catalyst in the agent B is at least one of methyl tributyl phosphine dimethyl phosphate, methyl trioctyl phosphine dimethyl phosphate and tetrabutyl phosphine acetate; the aliphatic polyhydric alcohol in the agent B is at least one of ethylene glycol, 1, 4-butanediol, 1, 6-hexanediol, neopentyl glycol and glycerol.

7. The method of using the LED die-molding packaging film according to claim 6, wherein: the agent B also includes a second heat stabilizer 1.0-5.0 wt.% and a second antioxidant 1.0-2.0 wt.%.

8. The method of using the LED die-pressing packaging film as claimed in claim 4, wherein: the bifunctional amine curing agent in the agent C is a bifunctional polyether amine curing agent, and the phosphorus-containing catalyst in the agent C is at least one of methyl tributyl phosphine dimethyl phosphate, methyl trioctyl phosphine dimethyl phosphate and tetrabutyl phosphine acetate.

9. The method of using the LED die attach encapsulant as recited in claim 8, wherein: the agent C also includes a third heat stabilizer 1.0-5.0 wt.%.

10. The method of using the LED die-molding encapsulating film according to claim 4, wherein: the inorganic powder in the D agent is SiO₂Powder of the SiO₂The powder is in an irregular structure, and the average grain diameter of the powder is 0.1-10 mu m; the surface tension control agent in the D agent comprises at least one of acrylic, organosilicon and fluorocarbon.

Technical Field

The invention relates to a use method of an LED packaging material, in particular to a use method of an LED mould pressing packaging film, and belongs to the technical field of materials for manufacturing LED lamps.

Background

The materials mainly comprise epoxy resin and organic silicon, the two materials have higher light transmittance and longer service life, particularly, the epoxy resin type packaging adhesive has better hardness, weather resistance and bonding property than the organic silicon type packaging adhesive, and is simple to produce and prepare, so that the epoxy resin type LED packaging adhesive is relatively more in practical use.

From the aspect of components, the common epoxy resin type LED packaging adhesive mainly comprises two parts, wherein the first part mainly comprises an epoxy resin component, liquid alicyclic epoxy resin, solid alicyclic epoxy resin or bisphenol A epoxy resin, a defoaming agent, a color complementing agent and the like; the second part mainly comprises a curing agent and an accelerator, wherein the curing agent is an acid anhydride curing agent, particularly a phthalic anhydride curing agent, and the accelerator is imidazole, quaternary ammonium salt and the like. When in use, the first part and the second part are mixed according to a certain proportion and then are placed in a mould, and then are heated and solidified at high temperature to form an irreversible solid form.

From the existing state, the currently commonly used LED molding packaging adhesive is divided into a solid adhesive cake and a liquid adhesive:

the solid rubber cake is solid packaging rubber which exists in a powder shape or rubber cake shape, the packaging rubber has higher requirement on storage condition, generally needs to be stored at a low temperature below 0 ℃, has very short storage life, and exists in a solid state form, particularly in a rubber cake shape which is common in the market, and due to higher crosslinking degree, auxiliary agents such as low light reflection materials, dispersing agents, anti-settling agents and the like and dyes and the like are difficult to be added into the rubber cake according to specific use requirements in the later use process, so that different use requirements are difficult to meet; and the design requirement of the die is high, and the material loss is large.

The liquid glue is improved to overcome the problems of the solid glue cake, is convenient for adding various additives and dyes for automatic blending when used at the later stage, but the liquid glue easily flows into a feeding ejector rod gap of a mould pressing mould when used due to high glue fluidity of the liquid glue, so that the glue in the gap is solidified when high-temperature solidification is carried out in the subsequent process, and the mould is blocked.

Disclosure of Invention

In order to solve the technical problem, the invention provides a use method of an LED mould pressing packaging film.

The technical scheme of the invention is as follows:

the invention discloses a use method of an LED mould pressing packaging film, which comprises the following steps:

(1) mixing 90-110 parts by weight of the agent A and 20-50 parts by weight of the agent C at normal temperature, stirring for 20-60min, and standing for 20min-24h to obtain a primary mixture; wherein

The agent A consists of a composition comprising the following components: 40-70 wt.% cycloaliphatic epoxy resin and 27-57 wt.% bisphenol a epoxy resin;

the agent C consists of a composition comprising the following components: 92-98 wt.% of bifunctional amine curing agent and 1-3 wt.% of phosphorus-containing catalyst;

(2) Mixing the preliminary mixture obtained in the step (1) with 70-140 parts by weight of the agent B, stirring for 10-50min, then adding 5-45 parts by weight of the agent D, mixing, and continuing stirring for 10-30min to obtain a thick colloidal mixture, wherein in the mixing and stirring process, a vacuum defoaming machine is used for defoaming; wherein

The agent B consists of a composition comprising the following components: 80-95 wt.% of a phthalic anhydride mixture at least consisting of hexahydrophthalic anhydride and methylhexahydrophthalic anhydride, 1-12 wt.% of a polyester diol, 0.5-3.0 wt.% of a phosphorus-containing catalyst, and 1-3 wt.% of an aliphatic polyol;

the agent D consists of a composition comprising the following components: 90-99.9 wt.% of inorganic powder and 0.1-10 wt.% of surface tension control agent;

(3) uniformly coating the thick colloidal mixture prepared in the step (2) on a release substrate in a wet coating mode, and baking at 70-130 ℃ for 1-3h to form a colloidal layer with the thickness of 10-200 mu m;

(4) standing the colloid layer obtained in the step (3) at normal temperature for 20-120min to obtain a meltable flaky solid film which is in a single sheet shape or a continuous roll shape;

(5) and (4) removing the release substrate from the sheet-shaped solid rubber sheet which can be melted back and is obtained in the step (4), covering the sheet-shaped solid rubber sheet on the LED particles in the mould pressing mould, heating at the temperature of 100-.

The further technical scheme is as follows:

and (4) covering the thin meltable sheet-like solid film obtained in the step (4) with a protective layer, wherein the protective layer is used for preventing the solid film from being polluted or being adhered by impurities.

The further technical scheme is as follows:

the protective layer is PE, PVC, EVA, PET or release paper.

The further technical scheme is as follows:

the release substrate is PET.

The further technical scheme is as follows:

the agent A also comprises 0.5-2.0 wt.% of adhesion promoter, 0.1-2.0 wt.% of defoamer, 0.5-2.0 wt.% of first antioxidant and 0.5-2.0 wt.% of first heat stabilizer.

Wherein the adhesion promoter is organosilane adhesion promoter and organosiloxane adhesion promoter, which is used for increasing the binding power of epoxy resin, and can be selected from bis [2- (3, 4-epoxycyclohexylethyl) ] tetramethylcyclotetrasiloxane, gamma- (2, 3-epoxypropoxy) propyl methyldimethoxysilane, gamma-methacryloxypropyl trimethoxysilane, 2,4, 6-tris [2- (3, 4-epoxycyclohexylethyl) ] tetramethylcyclotetrasiloxane and the like; the defoaming agent is a defoaming agent conventionally used in the field; the first antioxidant is phosphite ester antioxidant commonly used in the field; the first heat stabilizer is at least one of hindered phenol heat stabilizer, phosphite ester heat stabilizer and thioether heat stabilizer, and can also be a common heat stabilizer for other epoxy resin packaging adhesives.

Wherein the alicyclic epoxy resin in the agent A is at least one of Celloxide2000, Celloxide2080, CY179, 2021P, ERL4221 and ERLA6300, preferably at least one of Celloxide2000, Celloxide2080 and 2021P; the bisphenol A epoxy resin is at least one of NPEL127E, NPEL128E, DIC840S, DIC0191 and DY-128E, preferably at least one of NPEL127E and NPEL 128E.

The further technical scheme is as follows:

in the agent B, the mass percent content of hexahydrophthalic anhydride in the phthalic anhydride mixture is at least 60 wt%, and the mass percent content of methyl hexahydrophthalic anhydride in the phthalic anhydride mixture is at least 15 wt%, based on the total mass of the phthalic anhydride mixture in the agent B; the polyester diol in the agent B is polycarbonate diol, preferably aliphatic polycarbonate diol; the phosphorus-containing catalyst in the agent B is at least one of methyl tributyl phosphine dimethyl phosphate, methyl trioctyl phosphine dimethyl phosphate and tetrabutyl phosphine acetate, and the methyl tributyl phosphine dimethyl phosphate is preferred; the aliphatic polyhydric alcohol in the agent B is at least one of ethylene glycol, 1, 4-butanediol, 1, 6-hexanediol, neopentyl glycol and glycerol, and is preferably ethylene glycol.

The further technical scheme is as follows:

the agent B also includes a second heat stabilizer 1.0-5.0 wt.% and a second antioxidant 1.0-2.0 wt.%.

Wherein the second heat stabilizer is at least one of hindered phenol heat stabilizer, phosphite heat stabilizer and thioether heat stabilizer, and can also be other heat stabilizers commonly used for phthalic anhydride; the second antioxidant is a phosphite antioxidant commonly used in the art.

The further technical scheme is as follows:

the bifunctional amine curing agent in the agent C is a bifunctional polyether amine curing agent, and the phosphorus-containing catalyst in the agent C is at least one of methyl tributyl phosphine dimethyl phosphate, methyl trioctyl phosphine dimethyl phosphate and tetrabutyl phosphine acetate, preferably methyl tributyl phosphine dimethyl phosphate.

The further technical scheme is as follows:

the agent C also includes a third heat stabilizer 1.0-5.0 wt.%.

Wherein the third heat stabilizer is at least one of hindered phenol heat stabilizer, phosphite ester heat stabilizer and thioether heat stabilizer, and can also be a heat stabilizer commonly used by other amine curing agents.

The further technical scheme is as follows:

the inorganic powder in the D agent is SiO₂Powder of the SiO ₂The powder is in an irregular structure, and the average grain diameter of the powder is 0.1-10 mu m; the surface tension controlling agent in the agent D includes, but is not limited to, at least one of acrylic, silicone, and fluorocarbon, and may be other kinds of leveling agents conventionally used by those skilled in the art.

The beneficial technical effects of the invention are as follows:

the existing LED process is divided into a dispensing process and a mould pressing process, the application discloses a liquid mixture is formed by an agent A, an agent B, an agent C and an agent D by the packaging adhesive of the mould pressing process, the agent A and the agent C are mixed and stood at normal temperature to form a preliminary mixture during use, the preliminary mixture is mixed and stirred uniformly with the agent B and the agent D in sequence and subjected to vacuum defoaming to obtain a thick adhesive mixture, the thick adhesive mixture is coated on a release substrate and baked, and a meltable solid film is obtained after standing at normal temperature.

The solid film is in a solid sheet shape in the die before being packaged and molded, and can solve the problems that the conventional all-liquid packaging adhesive flows into a gap of a feeding ejector rod of the die due to high fluidity in the die pressing die, is solidified and clamped in the later period and has material loss, and the forming thickness and uniformity are difficult to control.

Moreover, the initial state of the packaging film when in use, namely the initial mixture is liquid with high fluidity, and the problem that other functional components are difficult to freely add in the packaging process according to the requirement of pure solid molding packaging adhesive in the market can be solved.

In addition, the pre-curing process reduces the internal stress of compression molding, and greatly improves the warping degree of the molded product.

The application the packaging film can be stored at normal temperature, has longer storage life, can realize the change of liquid state-pre-curing solid state-melting back viscous liquid state-completely curing solid state in the packaging process, and the product after mould pressing has the warping degree below 1%, has better bonding associativity, low hydroscopicity, excellent weather resistance, high hardness, low expansion coefficient, good water vapor resistance and the like, and the packaged LED lamp has good cold and hot shock performance, low lamp death rate and excellent normal temperature aging resistance.

Drawings

FIG. 1 is a flow chart of the present invention.

Detailed Description

In order to clearly understand the technical means of the present invention and to implement the technical means according to the content of the specification, the following embodiments and comparative examples are further described in detail, and the following examples are used for illustrating the present invention but not for limiting the scope of the present invention.

The preparation of the specific examples and comparative examples was carried out according to the formulations and amounts described in table 1:

table 1 amount of formulation (unit: wt.%) of specific examples and comparative examples

Note: the component is not used in the portion of 0 in the weight ratio of the agent A, the agent B, the agent C and the agent D.

Of the above-mentioned specific examples and comparative examples, comparative example 1 is the case where only the agent B is used as the curing agent, and comparative example 2 is the case where the agent D is not used.

The A, B, C and the D agents prepared in the above specific examples and comparative examples were used for die-molding and encapsulating LEDs according to the following method of using the LED die-molding encapsulating film:

the using method comprises the following steps: the methods of use described for specific examples 1-2 and comparative examples 1-2 herein.

(1) Mixing and stirring the agent A and the agent C according to the weight ratio at normal temperature for 20-60min, and then standing for 20-24 h to obtain a primary mixture.

(2) Mixing the primary mixture obtained in the step (1) and the agent B according to the weight part ratio, stirring for 10-50min, adding the agent D according to the weight part ratio, mixing, continuing stirring for 10-30min to obtain a thick gel mixture, and removing bubbles by using a vacuum defoaming machine in the mixing and stirring process;

(3) and (3) uniformly coating the thick colloidal mixture obtained in the step (2) on a release substrate in a wet coating mode at normal temperature, and baking for 1-3 hours at 70-130 ℃ by using an oven to form a colloidal layer with the thickness of 10-200 mu m, wherein the thick colloidal mixture can be coated on a single-piece release substrate with a specific length and width during coating, or coated on a continuous roll-shaped release substrate.

(4) And (4) standing the colloid layer obtained in the step (3) at normal temperature for 20-120min to obtain a single sheet type or rolled sheet type solid film capable of being melted back, and inspecting the surface condition of the solid film.

(5) And (4) removing the release substrate from the sheet-shaped solid film capable of being melted back obtained in the step (4), covering the sheet-shaped solid film on the LED particles, carrying out mould pressing in a mould pressing mould, heating the solid film at the temperature of 100-200 ℃ for 3-8min to melt back the solid film into viscous glue and coat the LED particles, achieving primary curing, and then heating the solid film at the temperature of 130-200 ℃ for 2-10h until the glue is completely cured, thereby completing the packaging operation of the LED particles.

In the process of forming the packaging film and LED die pressing packaging, the surface condition (namely film forming property) of the packaging film and the meltback performance of the packaging film are inspected. The surface condition (i.e., film formability) of the packaging film means that a uniform film without shrinkage cavities must be formed on a release substrate, so that a good effect can be obtained in a subsequent packaging process, and if the film is not uniform or has holes, defects may occur in the packaging process, thereby affecting the performance of the packaged LED. In the packaging process, considering that the peripheries of the LED chip and the gold wire are completely protected, the film must be heated and melted back to have fluidity to achieve a good packaging effect, so that the melting back performance of the packaging film needs to be considered, and whether the formed packaging film can be converted into a viscous liquid state at a certain temperature is mainly considered.

And after the LED die pressing packaging is finished, inspecting the performances of the packaged LED lamp, such as the warpage rate after curing, the die pressing curing time, the cold and hot shock performance, the PCT dead lamp rate and the normal temperature aging performance. In the mold curing time test, if the time is too long, the production efficiency is affected, and generally, the mold curing time is preferably less than 5 min. The cold and hot impact performance test condition is-40 ℃ (15min) → (10sec) → 100 ℃ (15min)/500 cycles, the electrical performance of the LED lamp is confirmed 100 times per cycle, and the total failure rate after 500cycles is less than 3%, so that the LED lamp is qualified. The PCT dead light rate test condition is that PCT (2 atmospheric pressure, 100% RH, 72h) is qualified without dead light. The normal temperature aging performance test is 1000hrs, and the blue light, red light and green light are qualified when the attenuation is within 5%.

If the film forming property of the film is not good or the mould pressing result is poor, the subsequent test is not carried out.

The performance test results are described in table 2.

TABLE 2 results of the Performance test of the specific examples and comparative examples

As can be seen from the test results in Table 2, when comparative example 1 is used, the film forming property is good, but the back-end packaging process cannot be carried out; in comparative example 2, only the agent D in example 1 is removed, so that a uniform film cannot be formed on a release substrate, and the subsequent operation is affected. The four formulations of the agent A, the agent B, the agent C and the agent D are used according to the using method, all the specific embodiments have good membrane appearance and packaging processability, and the packaging performance of the LED lamp is also excellent.

The application the packaging adhesive comprises an agent A, an agent B, an agent C and an agent D and is a liquid mixture, the agent A and the agent C are mixed and stood at normal temperature to form a primary mixture during use, then the primary mixture is uniformly mixed and stirred with the agent B and the agent D in sequence and subjected to vacuum defoaming to obtain a thick colloidal mixture, the thick colloidal mixture is uniformly coated on a release substrate and roasted to obtain a meltable solid film after standing at normal temperature, the solid film is directly covered on LED particles in a mould pressing mould when mould pressing packaging is formally carried out, the solid film is remelted into the viscous glue in the mould at a certain temperature, and then the LED particles can be cured and molded by further mould pressing heating to complete the packaging of the LED particles.

Therefore, the problem that the conventional full-liquid packaging adhesive flows into a gap of a feeding ejector rod of a die due to low fluidity in a die pressing die and is solidified and clamped in the later period can be solved; the initial state of the packaging film when in use, namely the initial mixture is liquid with high fluidity, and can solve the problems that the storage life of a pure solid molded packaging rubber block on the market is short and other functional components are difficult to freely add as required in the packaging process; in addition, the pre-curing process reduces the internal stress of compression molding, and greatly improves the warping degree of the molded product. The application the encapsulation film can be preserved at normal temperature, the shelf life is longer, can realize liquid-precuring solid-thick liquid-solid state of solidifying completely of melting back in the encapsulation process, and the product after the mould pressing has the angularity below 1%, has better bonding associativity, low hydroscopicity, excellent weatherability, high rigidity, low expansion coefficient, good water vapor resistance ability etc. the LED lamp cold and hot shock property after the encapsulation is good, the lamp rate of dying is low and normal atmospheric temperature aging resistance is excellent, and encapsulation thickness is even.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, it should be noted that, for those skilled in the art, many modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.